Fix hangs in Mandoline page cycler on Linux with --enable-multiprocess.

components/html_viewer/content_handler_impl.h

Index: components/html_viewer/content_handler_impl.h
diff --git a/components/html_viewer/content_handler_impl.h b/components/html_viewer/content_handler_impl.h
index 2edbf5ead85ba3738ab394b47c22f73f0135e676..0f0d27b63e9d1c13972c553f011858db08f1e5f4 100644
--- a/components/html_viewer/content_handler_impl.h
+++ b/components/html_viewer/content_handler_impl.h
@@ -27,12 +27,15 @@ class ContentHandlerImpl : public mojo::ContentHandler {
 
  private:
   // Overridden from ContentHandler:
-  void StartApplication(mojo::InterfaceRequest<mojo::Application> request,
-                        mojo::URLResponsePtr response) override;
+  void StartApplication(
+      mojo::InterfaceRequest<mojo::Application> request,
+      mojo::URLResponsePtr response,
+      const mojo::Callback<void()>& destruct_callback) override;
 
   GlobalState* global_state_;
   mojo::ApplicationImpl* app_;
   mojo::StrongBinding<mojo::ContentHandler> binding_;
+  scoped_ptr<mojo::AppRefCount> app_refcount_;
 
   DISALLOW_COPY_AND_ASSIGN(ContentHandlerImpl);
 };